* SPI driver for Micrel/Kendin KS8995M and KSZ8864RMN ethernet switches
*
* Copyright (C) 2008 Gabor Juhos <juhosg at openwrt.org>
+ * Copyright (C) 2025 Linus Walleij <linus.walleij@linaro.org>
*
* This file was based on: drivers/spi/at25.c
* Copyright (C) 2006 David Brownell
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/bits.h>
+#include <linux/if_bridge.h>
+#include <linux/if_vlan.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
-
#include <linux/spi/spi.h>
+#include <net/dsa.h>
#define DRV_VERSION "0.1.1"
#define DRV_DESC "Micrel KS8995 Ethernet switch SPI driver"
#define KS8995_REG_ID1 0x01 /* Chip ID1 */
#define KS8995_REG_GC0 0x02 /* Global Control 0 */
+
+#define KS8995_GC0_P5_PHY BIT(3) /* Port 5 PHY enabled */
+
#define KS8995_REG_GC1 0x03 /* Global Control 1 */
#define KS8995_REG_GC2 0x04 /* Global Control 2 */
+
+#define KS8995_GC2_HUGE BIT(2) /* Huge packet support */
+#define KS8995_GC2_LEGAL BIT(1) /* Legal size override */
+
#define KS8995_REG_GC3 0x05 /* Global Control 3 */
#define KS8995_REG_GC4 0x06 /* Global Control 4 */
+
+#define KS8995_GC4_10BT BIT(4) /* Force switch to 10Mbit */
+#define KS8995_GC4_MII_FLOW BIT(5) /* MII full-duplex flow control enable */
+#define KS8995_GC4_MII_HD BIT(6) /* MII half-duplex mode enable */
+
#define KS8995_REG_GC5 0x07 /* Global Control 5 */
#define KS8995_REG_GC6 0x08 /* Global Control 6 */
#define KS8995_REG_GC7 0x09 /* Global Control 7 */
#define KS8995_REG_GC8 0x0a /* Global Control 8 */
#define KS8995_REG_GC9 0x0b /* Global Control 9 */
-#define KS8995_REG_PC(p, r) ((0x10 * p) + r) /* Port Control */
-#define KS8995_REG_PS(p, r) ((0x10 * p) + r + 0xe) /* Port Status */
+#define KS8995_GC9_SPECIAL BIT(0) /* Special tagging mode (DSA) */
+
+/* In DSA the ports 1-4 are numbered 0-3 and the CPU port is port 4 */
+#define KS8995_REG_PC(p, r) (0x10 + (0x10 * (p)) + (r)) /* Port Control */
+#define KS8995_REG_PS(p, r) (0x1e + (0x10 * (p)) + (r)) /* Port Status */
+
+#define KS8995_REG_PC0 0x00 /* Port Control 0 */
+#define KS8995_REG_PC1 0x01 /* Port Control 1 */
+#define KS8995_REG_PC2 0x02 /* Port Control 2 */
+#define KS8995_REG_PC3 0x03 /* Port Control 3 */
+#define KS8995_REG_PC4 0x04 /* Port Control 4 */
+#define KS8995_REG_PC5 0x05 /* Port Control 5 */
+#define KS8995_REG_PC6 0x06 /* Port Control 6 */
+#define KS8995_REG_PC7 0x07 /* Port Control 7 */
+#define KS8995_REG_PC8 0x08 /* Port Control 8 */
+#define KS8995_REG_PC9 0x09 /* Port Control 9 */
+#define KS8995_REG_PC10 0x0a /* Port Control 10 */
+#define KS8995_REG_PC11 0x0b /* Port Control 11 */
+#define KS8995_REG_PC12 0x0c /* Port Control 12 */
+#define KS8995_REG_PC13 0x0d /* Port Control 13 */
+
+#define KS8995_PC0_TAG_INS BIT(2) /* Enable tag insertion on port */
+#define KS8995_PC0_TAG_REM BIT(1) /* Enable tag removal on port */
+#define KS8995_PC0_PRIO_EN BIT(0) /* Enable priority handling */
+
+#define KS8995_PC2_TXEN BIT(2) /* Enable TX on port */
+#define KS8995_PC2_RXEN BIT(1) /* Enable RX on port */
+#define KS8995_PC2_LEARN_DIS BIT(0) /* Disable learning on port */
+
+#define KS8995_PC13_TXDIS BIT(6) /* Disable transmitter */
+#define KS8995_PC13_PWDN BIT(3) /* Power down */
#define KS8995_REG_TPC0 0x60 /* TOS Priority Control 0 */
#define KS8995_REG_TPC1 0x61 /* TOS Priority Control 1 */
#define KS8995_CMD_WRITE 0x02U
#define KS8995_CMD_READ 0x03U
+#define KS8995_CPU_PORT 4
+#define KS8995_NUM_PORTS 5 /* 5 ports including the CPU port */
#define KS8995_RESET_DELAY 10 /* usec */
enum ks8995_chip_variant {
struct ks8995_switch {
struct spi_device *spi;
+ struct device *dev;
+ struct dsa_switch *ds;
struct mutex lock;
struct gpio_desc *reset_gpio;
struct bin_attribute regs_attr;
const struct ks8995_chip_params *chip;
int revision_id;
+ unsigned int max_mtu[KS8995_NUM_PORTS];
};
static const struct spi_device_id ks8995_id[] = {
return err;
}
+static int ks8995_check_config(struct ks8995_switch *ks)
+{
+ int ret;
+ u8 val;
+
+ ret = ks8995_read_reg(ks, KS8995_REG_GC0, &val);
+ if (ret) {
+ dev_err(ks->dev, "failed to read KS8995_REG_GC0\n");
+ return ret;
+ }
+
+ dev_dbg(ks->dev, "port 5 PHY %senabled\n",
+ (val & KS8995_GC0_P5_PHY) ? "" : "not ");
+
+ val |= KS8995_GC0_P5_PHY;
+ ret = ks8995_write_reg(ks, KS8995_REG_GC0, val);
+ if (ret)
+ dev_err(ks->dev, "failed to set KS8995_REG_GC0\n");
+
+ dev_dbg(ks->dev, "set KS8995_REG_GC0 to 0x%02x\n", val);
+
+ return 0;
+}
+
+static void
+ks8995_mac_config(struct phylink_config *config, unsigned int mode,
+ const struct phylink_link_state *state)
+{
+}
+
+static void
+ks8995_mac_link_up(struct phylink_config *config, struct phy_device *phydev,
+ unsigned int mode, phy_interface_t interface,
+ int speed, int duplex, bool tx_pause, bool rx_pause)
+{
+ struct dsa_port *dp = dsa_phylink_to_port(config);
+ struct ks8995_switch *ks = dp->ds->priv;
+ int port = dp->index;
+ int ret;
+ u8 val;
+
+ /* Allow forcing the mode on the fixed CPU port, no autonegotiation.
+ * We assume autonegotiation works on the PHY-facing ports.
+ */
+ if (port != KS8995_CPU_PORT)
+ return;
+
+ dev_dbg(ks->dev, "MAC link up on CPU port (%d)\n", port);
+
+ ret = ks8995_read_reg(ks, KS8995_REG_GC4, &val);
+ if (ret) {
+ dev_err(ks->dev, "failed to read KS8995_REG_GC4\n");
+ return;
+ }
+
+ /* Conjure port config */
+ switch (speed) {
+ case SPEED_10:
+ dev_dbg(ks->dev, "set switch MII to 100Mbit mode\n");
+ val |= KS8995_GC4_10BT;
+ break;
+ case SPEED_100:
+ default:
+ dev_dbg(ks->dev, "set switch MII to 100Mbit mode\n");
+ val &= ~KS8995_GC4_10BT;
+ break;
+ }
+
+ if (duplex == DUPLEX_HALF) {
+ dev_dbg(ks->dev, "set switch MII to half duplex\n");
+ val |= KS8995_GC4_MII_HD;
+ } else {
+ dev_dbg(ks->dev, "set switch MII to full duplex\n");
+ val &= ~KS8995_GC4_MII_HD;
+ }
+
+ dev_dbg(ks->dev, "set KS8995_REG_GC4 to %02x\n", val);
+
+ /* Enable the CPU port */
+ ret = ks8995_write_reg(ks, KS8995_REG_GC4, val);
+ if (ret)
+ dev_err(ks->dev, "failed to set KS8995_REG_GC4\n");
+}
+
+static void
+ks8995_mac_link_down(struct phylink_config *config, unsigned int mode,
+ phy_interface_t interface)
+{
+ struct dsa_port *dp = dsa_phylink_to_port(config);
+ struct ks8995_switch *ks = dp->ds->priv;
+ int port = dp->index;
+
+ if (port != KS8995_CPU_PORT)
+ return;
+
+ dev_dbg(ks->dev, "MAC link down on CPU port (%d)\n", port);
+
+ /* Disable the CPU port */
+}
+
+static const struct phylink_mac_ops ks8995_phylink_mac_ops = {
+ .mac_config = ks8995_mac_config,
+ .mac_link_up = ks8995_mac_link_up,
+ .mac_link_down = ks8995_mac_link_down,
+};
+
+static enum
+dsa_tag_protocol ks8995_get_tag_protocol(struct dsa_switch *ds,
+ int port,
+ enum dsa_tag_protocol mp)
+{
+ /* This switch actually uses the 6 byte KS8995 protocol */
+ return DSA_TAG_PROTO_NONE;
+}
+
+static int ks8995_setup(struct dsa_switch *ds)
+{
+ return 0;
+}
+
+static int ks8995_port_enable(struct dsa_switch *ds, int port,
+ struct phy_device *phy)
+{
+ struct ks8995_switch *ks = ds->priv;
+
+ dev_dbg(ks->dev, "enable port %d\n", port);
+
+ return 0;
+}
+
+static void ks8995_port_disable(struct dsa_switch *ds, int port)
+{
+ struct ks8995_switch *ks = ds->priv;
+
+ dev_dbg(ks->dev, "disable port %d\n", port);
+}
+
+static int ks8995_port_pre_bridge_flags(struct dsa_switch *ds, int port,
+ struct switchdev_brport_flags flags,
+ struct netlink_ext_ack *extack)
+{
+ /* We support enabling/disabling learning */
+ if (flags.mask & ~(BR_LEARNING))
+ return -EINVAL;
+
+ return 0;
+}
+
+static int ks8995_port_bridge_flags(struct dsa_switch *ds, int port,
+ struct switchdev_brport_flags flags,
+ struct netlink_ext_ack *extack)
+{
+ struct ks8995_switch *ks = ds->priv;
+ int ret;
+ u8 val;
+
+ if (flags.mask & BR_LEARNING) {
+ ret = ks8995_read_reg(ks, KS8995_REG_PC(port, KS8995_REG_PC2), &val);
+ if (ret) {
+ dev_err(ks->dev, "failed to read KS8995_REG_PC2 on port %d\n", port);
+ return ret;
+ }
+
+ if (flags.val & BR_LEARNING)
+ val &= ~KS8995_PC2_LEARN_DIS;
+ else
+ val |= KS8995_PC2_LEARN_DIS;
+
+ ret = ks8995_write_reg(ks, KS8995_REG_PC(port, KS8995_REG_PC2), val);
+ if (ret) {
+ dev_err(ks->dev, "failed to write KS8995_REG_PC2 on port %d\n", port);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static void ks8995_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
+{
+ struct ks8995_switch *ks = ds->priv;
+ int ret;
+ u8 val;
+
+ ret = ks8995_read_reg(ks, KS8995_REG_PC(port, KS8995_REG_PC2), &val);
+ if (ret) {
+ dev_err(ks->dev, "failed to read KS8995_REG_PC2 on port %d\n", port);
+ return;
+ }
+
+ /* Set the bits for the different STP states in accordance with
+ * the datasheet, pages 36-37 "Spanning tree support".
+ */
+ switch (state) {
+ case BR_STATE_DISABLED:
+ case BR_STATE_BLOCKING:
+ case BR_STATE_LISTENING:
+ val &= ~KS8995_PC2_TXEN;
+ val &= ~KS8995_PC2_RXEN;
+ val |= KS8995_PC2_LEARN_DIS;
+ break;
+ case BR_STATE_LEARNING:
+ val &= ~KS8995_PC2_TXEN;
+ val &= ~KS8995_PC2_RXEN;
+ val &= ~KS8995_PC2_LEARN_DIS;
+ break;
+ case BR_STATE_FORWARDING:
+ val |= KS8995_PC2_TXEN;
+ val |= KS8995_PC2_RXEN;
+ val &= ~KS8995_PC2_LEARN_DIS;
+ break;
+ default:
+ dev_err(ks->dev, "unknown bridge state requested\n");
+ return;
+ }
+
+ ret = ks8995_write_reg(ks, KS8995_REG_PC(port, KS8995_REG_PC2), val);
+ if (ret) {
+ dev_err(ks->dev, "failed to write KS8995_REG_PC2 on port %d\n", port);
+ return;
+ }
+
+ dev_dbg(ks->dev, "set KS8995_REG_PC2 for port %d to %02x\n", port, val);
+}
+
+static void ks8995_phylink_get_caps(struct dsa_switch *dsa, int port,
+ struct phylink_config *config)
+{
+ unsigned long *interfaces = config->supported_interfaces;
+
+ if (port == KS8995_CPU_PORT)
+ __set_bit(PHY_INTERFACE_MODE_MII, interfaces);
+
+ if (port <= 3) {
+ /* Internal PHYs */
+ __set_bit(PHY_INTERFACE_MODE_INTERNAL, interfaces);
+ /* phylib default */
+ __set_bit(PHY_INTERFACE_MODE_MII, interfaces);
+ }
+
+ config->mac_capabilities = MAC_SYM_PAUSE | MAC_10 | MAC_100;
+}
+
+/* Huge packet support up to 1916 byte packages "inclusive"
+ * which means that tags are included. If the bit is not set
+ * it is 1536 bytes "inclusive". We present the length without
+ * tags or ethernet headers. The setting affects all ports.
+ */
+static int ks8995_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
+{
+ struct ks8995_switch *ks = ds->priv;
+ unsigned int max_mtu;
+ int ret;
+ u8 val;
+ int i;
+
+ ks->max_mtu[port] = new_mtu;
+
+ /* Roof out the MTU for the entire switch to the greatest
+ * common denominator: the biggest set for any one port will
+ * be the biggest MTU for the switch.
+ */
+ max_mtu = ETH_DATA_LEN;
+ for (i = 0; i < KS8995_NUM_PORTS; i++) {
+ if (ks->max_mtu[i] > max_mtu)
+ max_mtu = ks->max_mtu[i];
+ }
+
+ /* Translate to layer 2 size.
+ * Add ethernet and (possible) VLAN headers, and checksum to the size.
+ * For ETH_DATA_LEN (1500 bytes) this will add up to 1522 bytes.
+ */
+ max_mtu += VLAN_ETH_HLEN;
+ max_mtu += ETH_FCS_LEN;
+
+ ret = ks8995_read_reg(ks, KS8995_REG_GC2, &val);
+ if (ret) {
+ dev_err(ks->dev, "failed to read KS8995_REG_GC2\n");
+ return ret;
+ }
+
+ if (max_mtu <= 1522) {
+ val &= ~KS8995_GC2_HUGE;
+ val &= ~KS8995_GC2_LEGAL;
+ } else if (max_mtu > 1522 && max_mtu <= 1536) {
+ /* This accepts packets up to 1536 bytes */
+ val &= ~KS8995_GC2_HUGE;
+ val |= KS8995_GC2_LEGAL;
+ } else {
+ /* This accepts packets up to 1916 bytes */
+ val |= KS8995_GC2_HUGE;
+ val |= KS8995_GC2_LEGAL;
+ }
+
+ dev_dbg(ks->dev, "new max MTU %d bytes (inclusive)\n", max_mtu);
+
+ ret = ks8995_write_reg(ks, KS8995_REG_GC2, val);
+ if (ret)
+ dev_err(ks->dev, "failed to set KS8995_REG_GC2\n");
+
+ return ret;
+}
+
+static int ks8995_get_max_mtu(struct dsa_switch *ds, int port)
+{
+ return 1916 - ETH_HLEN - ETH_FCS_LEN;
+}
+
+static const struct dsa_switch_ops ks8995_ds_ops = {
+ .get_tag_protocol = ks8995_get_tag_protocol,
+ .setup = ks8995_setup,
+ .port_pre_bridge_flags = ks8995_port_pre_bridge_flags,
+ .port_bridge_flags = ks8995_port_bridge_flags,
+ .port_enable = ks8995_port_enable,
+ .port_disable = ks8995_port_disable,
+ .port_stp_state_set = ks8995_port_stp_state_set,
+ .port_change_mtu = ks8995_change_mtu,
+ .port_max_mtu = ks8995_get_max_mtu,
+ .phylink_get_caps = ks8995_phylink_get_caps,
+};
+
/* ------------------------------------------------------------------------ */
static int ks8995_probe(struct spi_device *spi)
{
mutex_init(&ks->lock);
ks->spi = spi;
+ ks->dev = &spi->dev;
ks->chip = &ks8995_chip[variant];
ks->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset",
dev_info(&spi->dev, "%s device found, Chip ID:%x, Revision:%x\n",
ks->chip->name, ks->chip->chip_id, ks->revision_id);
+ err = ks8995_check_config(ks);
+ if (err)
+ return err;
+
+ ks->ds = devm_kzalloc(&spi->dev, sizeof(*ks->ds), GFP_KERNEL);
+ if (!ks->ds)
+ return -ENOMEM;
+
+ ks->ds->dev = &spi->dev;
+ ks->ds->num_ports = KS8995_NUM_PORTS;
+ ks->ds->ops = &ks8995_ds_ops;
+ ks->ds->phylink_mac_ops = &ks8995_phylink_mac_ops;
+ ks->ds->priv = ks;
+
+ err = dsa_register_switch(ks->ds);
+ if (err)
+ return dev_err_probe(&spi->dev, err,
+ "unable to register DSA switch\n");
+
return 0;
}
{
struct ks8995_switch *ks = spi_get_drvdata(spi);
+ dsa_unregister_switch(ks->ds);
/* assert reset */
gpiod_set_value_cansleep(ks->reset_gpio, 1);
}